In a long term evolution-advanced (LTE-A) system, a shared channel is used for transmitting data. After a user equipment (UE) establishes a radio bearer (RB) with an evolved base station (eNB), there is no fixed data uplink resource. When there exists uplink data to be transmitted, the UE requests an uplink resource from the eNB. After the eNB allocates an uplink resource, the UE sends the uplink data by using the uplink resource.
The UE may request an uplink resource from the eNB by adopting a buffer status report (BSR). The BSR is a more detailed notification manner, which may not only notify the eNB that the UE has data to be uploaded, but also notify the eNB of a size of the data to be transmitted.
Multiple logical channels of a UE may work simultaneously, and priority levels of these logical channels are different. In order to allow an eNB to know which logical channels have data to be transmitted and control a size of a BSR, the third generation partnership project (3GPP) groups the logical channels according to the priority levels, the group of the logical channels is configured by an upper layer signaling, and each logical channel group has a cache or buffer. When a BSR is reported, a data status of each buffer is reported to notify an eNB of a size of data to be transmitted in each logical channel group.
In an LTE-A system, in order to satisfy a requirement of the International Telecommunication Union on the peak data rate of the fourth generation communication technology, a carrier aggregation (CA) technology, also known as a spectrum aggregation or bandwidth extension technology, is introduced. In the carrier aggregation technology, frequency spectrums of two or more component carriers are aggregated together to obtain a wider transmission bandwidth. The carrier aggregation comprises a carrier aggregation in a base station and a carrier aggregation between base stations.
In a carrier aggregation in a base station, or in a carrier aggregation under a macro cell and a micro cell, between which there exists an ideal backhaul, for example, the macro cell and the micro cell are connected through an optical fiber (the micro cell may also be a cell within a coverage of a radio frequency head herein), a joint scheduling may be adopted among multiple carriers, namely, when scheduling a carrier in aggregated carriers, the eNB also knows a scheduling condition on another carrier. When allocating the uplink resource to a UE after receiving a BSR of the UE, the eNB may comprehensively consider a load and scheduling condition of each carrier to reasonably allocate a scheduling resource to the UE.
In the carrier aggregation between base stations or a carrier aggregation under a non-ideal backhaul condition, a real-time data transmission between the base stations could not be achieved. A typical application scenario is as follows. The macro cell mainly provides system information, a radio link monitoring and a mobility management in order to ensure a continuity of a service. Meanwhile, in order to ensure a continuity of a voice service, a semi-persistent scheduling service is also served by the macro cell generally. Multiple micro cells deployed within a coverage of the macro cell mainly provide a transmission of a high data rate service. In this case, the macro cell is a primary cell of a UE, and a corresponding macro base station is called a primary base station. The micro cell is a secondary cell of the UE, and a corresponding micro base station is called a secondary base station.
After receiving a BSR of the UE, the macro base station performs a classification based on service types corresponding to logical channel groups. For example, data corresponding to the semi-persistent scheduling service is kept and served by the macro cell, and the high data rate service is shunted to the micro cell. In the prior art, the macro base station and the micro base station passively and directly perform uplink split according to the service type of the uplink data, so that the flexibility is poor.